|
russian building code
is anybody familiar with the "building codes of russia", snip 2.01.07-85? section 5.7 in the snow loads chapter talks about a reliability coefficient. are they referring to a load factor as in lrfd? in other words is the design philosophy of this code lrfd and is this reliabilty factor what we in the us call a load factor (or overload factor)?
the reason i'm asking is i usually use asd but if this reliabilty factor is really intended to be used with lrfd i don't want to penalize myself by factoring up the load and reducing my strength by dividing by a factor of safety.
years ago i was told the system of limit states design originated in the former soviet union. (i'll probably be slammed by all the history buffs who frequent the engineering history forum.)
relatively speaking, you will get the same sizes for beams and columns as you get when using asd, except where dead loads are large and live loads are small. then you will usually get a slightly smaller
load factors that used in russia are between 1.1 and 1.2
this is conservative for asd, but not enough for lrfd.
i would use it with asd.
good luck.
whymrg,
thanks for the input. i'm still confused though because section 5.7 of snip gives a "reliabilty factor", as they call it, of 1.6. sounds like lrfd to me.
rkillian, i was working for a russian job few month ago, and i used din codes to design steel and concrete structures, because it was not possible to understand the snip regulations. but i asked some russian eng. about this issue, and they told me that the reliability factors are similar to loads factor used by aci 318 or lrfd. so if you are using asd you must not use these factors.
russian snip used to have uniform load factors (overload) for steel, concrete masonry and wood:
dead load 1.1
snow 1.3
short-term live load 1.3(guess)
long term live load 1.3 (guess)
wind 1.4 plus dynamic component for buildings of certain height
as far as i remember overload factors and reliability factors had different physical meaning: it depends on context. but i am not sure.
i think you can design by asd using corresponding steel
specification however local engineers would prefer lrfd.
if you need interpretation of any snip paragraph (english or russian) let me know. |
|